The present invention relates to a laminate sheet construction. More particularly, the present invention relates to a laminated material having cross-laminated plastic film layers.
Cross-laminates of uniaxially oriented films from crystalline polymers are known to exhibit a number of beneficial properties including improved tear resistance, as for example is disclosed in Rasmussen, U.S. Pat. No. 3,322,613, the disclosure of which is incorporated herein by reference. A more modern discussion of forming multi-layer, oriented or “bias-cut” plastic films is described in Barnes et al., U.S. Pat. No. 6,284,344, the disclosure of which is incorporated herein by reference.
Despite advances in multi-layer film technology, use of such films as the strength layer in a laminated structure with paperboard are still characterized by relatively poor tear characteristics. In effect, the poor tear characteristics of the paperboard are imparted to the cross-laminated layers and the tear propagates through each of the layers. Also, in fabricating products, the dissimilar materials of such laminates can present a number of problems including poor adhesion of the film to the paper board surface, which can result in spalling and other undesirable characteristics in the finished laminated product.
Accordingly, there is a need for a highly tear resistant laminate. Preferably such a laminate is formed using known material and known manufacturing methods.